Title of article :
Perfectness of the essential graph for modules over commutative rings
Author/Authors :
Soheilnia ، Fatemeh Department of Pure Mathematics - Faculty of Science - Imam Khomieini International University , Payrovi ، Shiroyeh Department of Pure Mathematics - Faculty of Science - Imam Khomieini International University , Behtoei ، Ali Department of Pure Mathematics - Faculty of Science - Imam Khomieini International University
Abstract :
Let R be a commutative ring and M be an R-module. The essential graph of M, denoted by EG(M) is a simple graph with vertex set Z(M) \ Ann(M) and two distinct vertices x, y ∈ Z(M) \ Ann(M) are adjacent if and only if AnnM(xy) is an essential submodule of M. In this paper, we investigate the dominating set, the clique and the chromatic number and the metric dimension of the essential graph for Noetherian modules. Let M be a Noetherian R-module such that |MinAssR(M)| = n ≥ 2 and let EG(M) be a connected graph. We prove that EG(M) is a weakly prefect, that is, ω(EG(M)) = χ(EG(M)). Furthermore, it is shown that dim(EG(M)) = |Z(M)| − (| Ann(M)| + 2n), whenever r(Ann(M)) ̸= Ann(M) and dim(EG(M)) = |Z(M)| − (| Ann(M)| + 2n − 2), whenever r(Ann(M)) = Ann(M)
Keywords :
Essential graph , Dominating set , Clique number , Chromatic number , Metric dimension
Journal title :
AUT Journal of Mathematics and Computing
Journal title :
AUT Journal of Mathematics and Computing